Sto provando per la prima volta :bubu: a far visualizzare in HTML un documento XML, ma ho un problema: ho un documento .XML e una pagina .HTML distinte, come faccio a dire alla mia pagina HTML di prendere quel determinato foglio XML?

Allora: il mio file prova.XML è così composto:
Codice PHP:
<?xml version="1.0" encoding="iso-8859-1"?>
<!DOCTYPE EMAIL [
 <!ELEMENT EMAIL (TO, FROM, CC, SUBJECT, BODY)> 
  <!ELEMENT TO (#PCDATA)> 
  <!ELEMENT FROM (#PCDATA)>
  <!ELEMENT CC (#PCDATA)>
  <!ELEMENT SUBJECT (#PCDATA)>
  <!ELEMENT BODY (#PCDATA)>
 ] >

<EMAIL>
    <TO>Jodie@msn.com</TO>
    <FROM>Bill@msn.com</FROM>
    <CC>Philip@msn.com</CC>
    <SUBJECT>My first DTD</SUBJECT>
    <BODY>Hello, World</BODY>
</EMAIL>
<EMAIL>
    <TO>Jodie@msn.com</TO>
    <FROM>Bill@msn.com</FROM>
    <CC>Philip@msn.com</CC>
    <SUBJECT>My first DTD</SUBJECT>
    <BODY>Hello, World</BODY>
</EMAIL>
Mentre il file prova.HTML è:
Codice PHP:
<HTML xmlns:xsl="http://www.w3.org/1999/XSL/Trasform"
      xmlns="http://www.w3.org/HTML4/" >
<BODY>
                <TABLE border="2">
                    <TR>
                        <td>TO</td>
                        <td>FROM</td>
                        <td>CC</td>
                        <td>Titolo</td>
                        <td>Body</td>
                    </TR>
                    <xsl:for-each select="EMAIL">
                    <TR>
                        <td><xsl:value-of select="TO" /></td>
                        <td><xsl:value-of select="FROM" /></td>
                        <td><xsl:value-of select="CC" /></td>
                        <td><xsl:value-of select="SUBJECT" /></td>
                        <td><xsl:value-of select="BODY" /></td>
                    </TR>
                    </xsl:for-each>
                </TABLE>
</BODY>
</HTML> 
Dove devo inserire in prova.HTML un riferimento a prova.XML?